Sitting in his office the day after chairing his final meeting with the Antiquities Advisory Board, Bernard Chan appeared relieved to have put the heritage hot seat behind him.

Chan, known as "the king of public duty" for the many public posts he has held, stepped down as chairman yesterday after six years with the advisory body. He declined to have his term renewed after a prolonged controversy about the future of the west wing of the government's former headquarters.

"It's a bit ironic," Chan said in an interview with the South China Morning Post. "Six years ago when I joined the board as a member, people challenged our vote on Queen's Pier [now demolished]. Six years on, people are still quarrelling about the way we vote. That's the reason I left," he said.

Under his leadership, the board has largely completed grading 1,444 historic sites across the city, with vigorous discussions about their historic value. "I thought I had improved the transparency and openness of the proceedings, but somehow the voting part remained contentious," Chan said.

Chan first resigned in June after being criticised for casting a tie-breaking vote to give the 52-year-old west wing a grade two listing - meaning it is not especially safe from demolition. He later did a U-turn, agreeing to remain on the board for a while, after fellow members asked him to stay.

He acknowledged a key difficulty in the board's relationship with the government. "Despite our advisory role, the public has an expectation we are the heritage watchdog," Chan said. "But our gradings are only an internal assessment, and the government may not always follow [our advice]. Our ad hoc approach of dealing with heritage owners case by case is undesirable."

In one case, officials backtracked on a plan to declare Ho Tung Gardens - a private property on The Peak - a monument, despite the antiquities board's unanimous support for that status. The officials were deterred by the owner's demand for HK$7 billion in return for preserving the building.

"If officials had insisted on making Ho Tung Gardens a monument, I am sure a public debate would have begun on what kind of heritage do we want to preserve at all costs," he said.

"We could have set a benchmark - say, paying to preserve only those structures people have a collective memory of. But now they have dodged the question, which is a failure."

He said he hoped the government could establish what the benchmark was soon.

In last summer's controversy over the west wing of the old government headquarters, officials said their scheme to redevelop the block would go ahead no matter what grading the antiquities board gave the 52-year-old building.

The dispute ended when the board gave the structure a grade one rating in mid-December, making it a potential monument. That happened after officials, under public pressure, decided to scrap the redevelopment plan.

Chan hopes to see a review of heritage policy in the second half of 2013, and a public debate about how much people are willing to pay for heritage.

This article appeared in the South China Morning Post print edition as We can do better, says outgoing antiquities chief